Dual colonization of Mucoromycotina and Glomeromycotina fungi in the basal liverwort, Haplomitrium mnioides (Haplomitriopsida).

In general, Glomeromycotina was thought to be the earliest fungi forming mycorrhiza-like structure (MLS) in land plant evolution. In contrast, because the earliest divergent lineage of extant land plants, i.e. Haplomitriopsida liverworts, associates only with Mucoromycotina mycobionts, recent studies suggested that those fungi are novel candidates for the earliest mycobionts. Therefore, Mucoromycotina-Haplomitriopsida association currently attracts attention as an ancient mycorrhiza-like association. However, mycobionts were identified in only 7 of 16 Haplomitriopsida species and the mycobionts diversity of this lineage is largely unclarified. To clarify the taxonomic composition of mycobionts in Haplomitriopsida, we observed MLSs in the rhizome of Haplomitrium mnioides (Haplomitriopsida), the Asian representative Haplomitriopsida species, and conducted molecular identification of mycobionts. It was recorded for the first time that Glomeromycotina and Mucoromycotina co-occur in Haplomitriopsida as mycobionts. Significantly, the arbuscule-like branching (ALB) of Glomeromycotina was newly described. As the Mucoromycotina fungi forming MLSs in H. mnioides, Endogonaceae and Densosporaceae were detected, in which size differences of hyphal swelling (HS) were found between the fungal families. This study provides a novel evidence in the MLS of Haplomitriopsida, i.e. the existence of Glomeromycotina association as well as the dominant Mucoromycotina association. In addition, since hyphal characteristics of the HS-type MLS were quite similar to those of fine endophytes (FE) of Endogonales in other bryophytes and vascular plants previously described, this MLS is suggested to be included in FE. These results suggest that Glomeromycotina and Mucoromycotina were acquired concurrently as the mycobionts by the earliest land plants evolved into arbuscular mycorrhizae and FE. Therefore, dual association of Haplomitriopsida, with Endogonales and Glomeromycotina will provide us novel insight on how the earliest land plants adapted to terrestrial habitats with fungi.

Functional complementarity of ancient plant-fungal mutualisms: contrasting nitrogen, phosphorus and carbon exchanges between Mucoromycotina and Glomeromycotina fungal symbionts of liverworts.

Liverworts, which are amongst the earliest divergent plant lineages and important ecosystem pioneers, often form nutritional mutualisms with arbuscular mycorrhiza-forming Glomeromycotina and fine-root endophytic Mucoromycotina fungi, both of which coevolved with early land plants. Some liverworts, in common with many later divergent plants, harbour both fungal groups, suggesting these fungi may complementarily improve plant access to different soil nutrients. We tested this hypothesis by growing liverworts in single and dual fungal partnerships under a modern atmosphere and under 1500 ppm [CO2 ], as experienced by early land plants. Access to soil nutrients via fungal partners was investigated with 15 N-labelled algal necromass and 33 P orthophosphate. Photosynthate allocation to fungi was traced using 14 CO2 . Only Mucoromycotina fungal partners provided liverworts with substantial access to algal 15 N, irrespective of atmospheric CO2 concentration. Both symbionts increased 33 P uptake, but Glomeromycotina were often more effective. Dual partnerships showed complementarity of nutrient pool use and greatest photosynthate allocation to symbiotic fungi. We show there are important functional differences between the plant-fungal symbioses tested, providing new insights into the functional biology of Glomeromycotina and Mucoromycotina fungal groups that form symbioses with plants. This may explain the persistence of the two fungal lineages in symbioses across the evolution of land plants.

Ancient plants with ancient fungi: liverworts associate with early-diverging arbuscular mycorrhizal fungi.

Arbuscular mycorrhizas are widespread in land plants including liverworts, some of the closest living relatives of the first plants to colonize land 500 million years ago (MYA). Previous investigations reported near-exclusive colonization of liverworts by the most recently evolved arbuscular mycorrhizal fungi, the Glomeraceae, indicating a recent acquisition from flowering plants at odds with the widely held notion that arbuscular mycorrhizal-like associations in liverworts represent the ancestral symbiotic condition in land plants. We performed an analysis of symbiotic fungi in 674 globally collected liverworts using molecular phylogenetics and electron microscopy. Here, we show every order of arbuscular mycorrhizal fungi colonizes early-diverging liverworts, with non-Glomeraceae being at least 10 times more common than in flowering plants. Arbuscular mycorrhizal fungi in liverworts and other ancient plant lineages (hornworts, lycopods, and ferns) were delimited into 58 taxa and 36 singletons, of which at least 43 are novel and specific to liverworts. The discovery that early plant lineages are colonized by early-diverging fungi supports the hypothesis that arbuscular mycorrhizas are an ancestral symbiosis for all land plants.

From rhizoids to roots? Experimental evidence of mutualism between liverworts and ascomycete fungi.

Background and Aims: The rhizoids of leafy liverworts (Jungermanniales, Marchantiophyta) are commonly colonized by the ascomycete fungus Pezoloma ericae. These associations are hypothesized to be functionally analogous to the ericoid mycorrhizas (ErMs) formed by P. ericae with the roots of Ericaceae plants in terms of bi-directional phosphorus for carbon exchange; however, this remains unproven. Here, we test whether associations between the leafy liverwort Cephalozia bicuspidata and P. ericae are mutualistic. Methods: We measured movement of phosphorus and carbon between C. bicuspidata and P. ericae using [33P]orthophosphate and 14CO2 isotope tracers in monoxenic cultures. We also measured leafy liverwort growth, with and without P. ericae. Key Results: We present the first demonstration of nutritionally mutualistic symbiosis between a non-vascular plant and an ErM-forming fungus, showing transfer of fungal-acquired P to the liverwort and of liverwort-fixed C to the fungus alongside increased growth in fungus-colonized liverworts. Conclusions: Thus, this ascomycete-liverwort symbiosis can now be described as mycorrhiza-like, providing further insights into ericoid mycorrhizal evolution and adding Ascomycota fungi to mycorrhizal fungal groups engaging in mutualisms with plants across the land plant phylogeny. As P. ericae also colonizes the rhizoids of Schistochilaceae liverworts, which originated in the Triassic and are sister to all other jungermannialean liverworts associated with fungi, our findings point toward an early origin of ascomycete-liverwort symbioses, possibly pre-dating their evolution in the Ericales by some 150 million years.

Functional analysis of liverworts in dual symbiosis with Glomeromycota and Mucoromycotina fungi under a simulated Palaeozoic CO2 decline.

Most land plants form mutualistic associations with arbuscular mycorrhizal fungi of the Glomeromycota, but recent studies have found that ancient plant lineages form mutualisms with Mucoromycotina fungi. Simultaneous associations with both fungal lineages have now been found in some plants, necessitating studies to understand the functional and evolutionary significance of these tripartite associations for the first time. We investigate the physiology and cytology of dual fungal symbioses in the early-diverging liverworts Allisonia and Neohodgsonia at modern and Palaeozoic-like elevated atmospheric CO2 concentrations under which they are thought to have evolved. We found enhanced carbon cost to liverworts with simultaneous Mucoromycotina and Glomeromycota associations, greater nutrient gain compared with those symbiotic with only one fungal group in previous experiments and contrasting responses to atmospheric CO2 among liverwort-fungal symbioses. In liverwort-Mucoromycotina symbioses, there is increased P-for-C and N-for-C exchange efficiency at 440 p.p.m. compared with 1500 p.p.m. CO2. In liverwort-Glomeromycota symbioses, P-for-C exchange is lower at ambient CO2 compared with elevated CO2. No characteristic cytologies of dual symbiosis were identified. We provide evidence of a distinct physiological niche for plant symbioses with Mucoromycotina fungi, giving novel insight into why dual symbioses with Mucoromycotina and Glomeromycota fungi persist to the present day.

Sebacina vermifera: a unique root symbiont with vast agronomic potential.

The Sebacinales belong to a taxonomically, ecologically, and physiologically diverse group of fungi in the Basidiomycota. While historically recognized as orchid mycorrhizae, recent DNA studies have brought to light both their pandemic distribution and the broad spectrum of mycorrhizal types they form. Indeed, ecological studies using molecular-based methods of detection have found Sebacinales fungi in field specimens of bryophytes (moss), pteridophytes (fern) and all families of herbaceous angiosperms (flowering plants) from temperate, subtropical and tropical regions. These natural host plants include, among others, liverworts, wheat, maize and Arabidopsis thaliana, the model plant traditionally viewed as non-mycorrhizal. The orchid mycorrhizal fungus Sebacina vermifera (MAFF 305830) was first isolated from the Australian orchid Cyrtostylis reniformis. Research performed with this strain clearly indicates its plant growth promoting abilities in a variety of plants, while demonstrating a lack of specificity that rivals or even surpasses that of arbuscular mycorrhizae. Indeed, these traits thus far appear to characterize a majority of strains belonging to the so-called "clade B" within the Sebacinales (recently re-classified as the Serendipitaceae), raising numerous basic research questions regarding plant-microbe signaling and the evolution of mycorrhizal symbioses. Further, given their proven beneficial impact on plant growth and their apparent but cryptic ubiquity, sebacinoid fungi should be considered as a previously hidden, but amenable and effective microbial tool for enhancing plant productivity and stress tolerance.

Secondary metabolites from Aspergillus fumigatus, an endophytic fungus from the liverwort Heteroscyphus tener (Steph.) Schiffn.

Three new metabolites, asperfumigatin (1), isochaetominine (10), and 8'-O-methylasterric acid (21), together with nineteen known compounds, were obtained from the culture of Aspergillus fumigatus, an endophytic fungus from the Chinese liverwort Heteroscyphus tener (Steph.) Schiffn. Their structures were established by extensive analysis of the spectroscopic data. The absolute configurations of 1 and 10 were determined by analysis of their respective CD spectra. Cytotoxicity of these isolates against four human cancer cell lines was also determined.

Paenibacillus herberti sp. nov., an endophyte isolated from Herbertus sendtneri.

Strain R33(T), an endophyte recovered from Herbertus sendtneri, was identified as representing a novel species of the genus Paenibacillus by using a polyphasic taxonomic approach. The novel strain was observed to be a Gram-stain positive, aerobic, rod-shaped, motile and endospore-forming bacterium. The major polar lipids of strain R33(T) were identified as diphosphatidylglycerol, phosphatidylethanolamine, along with lesser amounts of phosphatidylglycerol, three unidentified aminophospholipids, two unidentified phospholipids and two unidentified lipids. The predominant isoprenoid quinone was identified as MK-7. The major fatty acids (>8.0 %) were found to be anteiso-C15:0 (40.0 %), C16:1 ω11c (9.4 %), C16:1 ω7c alcohol (8.5 %) and C16:0 (8.2 %). The diamino acid found in the cell-wall peptidoglycan was meso-diaminopimelic acid. The G+C content of genomic DNA was determined to be 56.9 mol%. The 16S rRNA gene sequence similarities of strain R33(T) to other Paenibacillus species ranged from 91.6 to 97.2 %, with high similarities to Paenibacillus humicus PC-147(T) and Paenibacillus pasadenensis SAFN-007(T). The phylogenetic analyses based on 16S rRNA gene sequences and the partial rpoB gene confirmed that strain R33(T) belongs to the genus Paenibacillus. However, strain R33(T) shows differential molecular characteristics compared to other related Paenibacillus species based on 16S rDNA-RFLP analyses; the DNA-DNA relatedness values between strain R33(T) and P. humicus PC-147(T), and that between strain R33(T) and P. pasadenensis SAFN-007(T), were 35.0 ± 2.0 and 41.4 ± 0.9 %, respectively. Based on its phenotypic, chemotaxonomic and phylogenetic properties, strain R33(T) is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus herberti is proposed (type strain R33(T) = CGMCC 1.15042(T) = DSM 29849(T)).

Naphtho-γ-pyrones from Endophyte Aspergillus niger occurring in the liverwort Heteroscyphus tener (Steph.) Schiffn.

Bioactivity-guided fractionation of the cytotoxic extract of Aspergillus niger, an endophytic fungus from the Chinese liverwort Heteroscyphus tener (Steph.) Schiffn., afforded five new naphtho-γ-pyrones, rubrofusarin-6-O-α-D-ribofuranoside (1), (R)-10-(3-succinimidyl)-TMC-256A1 (2), asperpyrone E (3), isoaurasperone A (4), and isoaurasperone F (5), as well as four known ones, dianhydroaurasperone C (6), aurasperone D (7), asperpyrone D (8), and asperpyrone A (9), together with a cytotoxic cyclic pentapeptide, malformin A1 (10). Their structures were determined by extensive spectroscopic analysis. The absolute configurations of dimeric naphtho-γ-pyrones 3-9 were also determined by analysis of their respective CD spectra.

Antimicrobial activity and cytotoxicity of endophytes from Scapania verrucosa Heeg.

We evaluated the antibacterial activity and cytotoxicity of endophytes isolated from Scapania verrucosa Heeg., which belongs to the liverwort class. A total of 49 endophytic fungi were isolated from S. verrucosa and classified into seven genera and one family in our previous study. In this study, the cytotoxic activity of the endophytes was assessed using the brine shrimp lethality bioassay, seven of which showed potent toxicity against the brine shrimp with 50% lethal concentration values less than 20 µg/mL. T-30 was the most toxic, with a 50% lethal concentration value of 7.15 µg/mL. Moreover, T-27 exhibited the strongest antibacterial activity against Staphylococcus aureus, with minimal inhibitory concentrations below 0.25 and 4 mg/mL, which can inhibit the growth of two standard strains - ATCC 25923 (methicillin-sensitive S. aureus) and ATCC 43300 (methicillin-resistant S. aureus) - in a time-dependent manner, respectively. These results suggest that endophytes in S. verrucosa are the sources for the production of natural bioactive products and thus warrant further investigation.

Diversity and cold adaptation of culturable endophytic fungi from bryophytes in the Fildes Region, King George Island, maritime Antarctica.

Endophytic fungi associated with three bryophyte species in the Fildes Region, King George Island, maritime Antarctica, that is, the liverwort Barbilophozia hatcheri, the mosses Chorisodontium aciphyllum and Sanionia uncinata, were studied by culture-dependent method. A total of 128 endophytic fungi were isolated from 1329 tissue segments of 14 samples. The colonization rate of endophytic fungi in three bryophytes species were 12.3%, 12.1%, and 8.7%, respectively. These isolates were identified to 21 taxa, with 15 Ascomycota, 5 Basidiomycota, and 1 unidentified fungus, based on morphological characteristics and sequence analyses of ITS region and D1/D2 domain. The dominant fungal endophyte was Hyaloscyphaceae sp. in B. hatcheri, Rhizoscyphus sp. in C. aciphyllum, and one unidentified fungus in S. uncinata; and their relative frequencies were 33.3%, 32.1%, and 80.0%, respectively. Furthermore, different Shannon-Weiner diversity indices (0.91-1.99) for endophytic fungi and low endophytic fungal composition similarities (0.19-0.40) were found in three bryophyte species. Growth temperature tests indicated that 21 taxa belong to psychrophiles (9), psychrotrophs (11), and mesophile (1). The results herein demonstrate that the Antarctic bryophytes are an interesting source of fungal endophytes and the endophytic fungal composition is different among the bryophyte species, and suggest that these fungal endophytes are adapted to cold stress in Antarctica.

Methylobacteria isolated from bryophytes and the 2-fold description of the same microbial species.

On the surface of healthy land plants (embryophytes), numerous non-pathogenic bacteria have been discovered and described. Among these epiphytic microbes, pink-pigmented facultative methylotrophic microbes of the genus Methylobacterium are of special significance, because these microorganisms consume methanol emitted via the stomatal pores and secrete growth-promoting phytohormones. Methylobacterium funariae, Schauer and Kutschera 2011, a species isolated in our lab from the common cord moss, described as a nova species in this journal, was recently characterized for a second time as a "new taxon" under a different name, "M. bullatum." Based on a phylogenetic analysis, we show that these taxa are identical. In addition, we provide novel information on the exact cell size, and describe the correct type locality of this bacterial species, which was classified as a phytosymbiont. Finally, we discuss the hypothesis that certain methylobacteria may preferentially colonize bryophytes. With reference to our recent discovery that thalli of ferns form, like liverworts and moss protonemata, associations with methylobacteria, we argue that the haploid phase of cryptogames are preferred host organisms of these pink-pigmented microbial phytosymbionts.

Mollicutes-related endobacteria thrive inside liverwort-associated arbuscular mycorrhizal fungi.

Arbuscular mycorrhizal fungi (AMF) can host Gram-positive endobacteria (BLOs) in their cytoplasm. These have been identified as Mollicutes-related microbes based on an inventory of AMF spores from fungal collections. Bacteria-like organisms (BLOs) of unknown identity have also been reported in the cytoplasm of AMF associated with liverworts, the earliest-diverged extant lineage of land plants. A combination of morphological, molecular and phylogenetic analyses revealed that three samples of two liverwort species (Conocephalum conicum and Lunularia cruciata) growing spontaneously in a botanical garden harboured AMF belonging to Glomerales, and these, in turn, hosted coccoid BLOs. 16S rDNA sequences from these BLOs clustered with the Mollicutes sequences identified from the spore collections but revealed the presence of novel phylotypes. Electron microscopy and fluorescence in situ hybridization (FISH) confirmed the presence of BLOs inside the cytoplasm of AMF hyphae colonizing the liverwort thalli. The high genetic variability of BLOs in liverwort-AMF associations thriving in the same ecological niche raises questions about the mechanisms underlying such diversity.

The thalloid liverwort Plagiochasma rupestre supports arbuscular mycorrhiza-like symbiosis in vitro.

In the present study, we obtained in vitro dual cultures between the liverwort Plagiochasma rupestre and two arbuscular mycorrhizal (AM) fungi: Glomus intraradices and Glomus clarum. Four agarized culture media were tested for optimal growth of P. rupestre. Also, a description of the symbiotic association is provided. Plagiochasma rupestre gametophytes profusely grew axenically in MM with sucrose, and thalli were successfully subcultured under these growth conditions. Arbuscular mycorrhizal fungal hyphae colonized P. rupestre thalli through rhizoids or by forming appresoria in the ventral thallus cells. Arbuscules, mycelia and structures resembling intrathallic spores or vesicles were developed in the internal parenchymatic cells. The pattern of AM colonization in P. rupestre was very similar to the Paris-type. After 100 days of dual culture, the external mycelia of both AM fungal strains formed thousands of small viable spores, suggesting that P. rupestre in vitro culture could be a valuable tool for studying the biology of both symbiotic partners and conserving AM fungi in in vitro germplasm collections.

Arabinogalactan proteins occur in the free-living cyanobacterium genus Nostoc and in plant-Nostoc symbioses.

Arabinogalactan proteins (AGP) are a diverse family of proteoglycans associated with the cell surfaces of plants. AGP have been implicated in a wide variety of plant cell processes, including signaling in symbioses. This study investigates the existence of putative AGP in free-living cyanobacterial cultures of the nitrogen-fixing, filamentous cyanobacteria Nostoc punctiforme and Nostoc sp. strain LBG1 and at the symbiotic interface in the symbioses between Nostoc spp. and two host plants, the angiosperm Gunnera manicata (in which the cyanobacterium is intracellular) and the liverwort Blasia pusilla (in which the cyanobacterium is extracellular). Enzyme-linked immunosorbent assay, immunoblotting, and immunofluorescence analyses demonstrated that three AGP glycan epitopes (recognized by monoclonal antibodies LM14, MAC207, and LM2) are present in free-living Nostoc cyanobacterial species. The same three AGP glycan epitopes are present at the Gunnera-Nostoc symbiotic interface and the LM2 epitope is detected during the establishment of the Blasia-Nostoc symbiosis. Bioinformatic analysis of the N. punctiforme genome identified five putative AGP core proteins that are representative of AGP classes found in plants. These results suggest a possible involvement of AGP in cyanobacterial-plant symbioses and are also suggestive of a cyanobacterial origin of AGP.

Contrasting arbuscular mycorrhizal responses of vascular and non-vascular plants to a simulated Palaeozoic CO2 decline.

The arbuscular mycorrhizal (AM) fungal symbiosis is widely hypothesized to have promoted the evolution of land plants from rootless gametophytes to rooted sporophytes during the mid-Palaeozoic (480-360 Myr, ago), at a time coincident with a 90% fall in the atmospheric CO(2) concentration ([CO(2)](a)). Here we show using standardized dual isotopic tracers ((14)C and (33)P) that AM symbiosis efficiency (defined as plant P gain per unit of C invested into fungi) of liverwort gametophytes declines, but increases in the sporophytes of vascular plants (ferns and angiosperms), at 440 p.p.m. compared with 1,500 p.p.m. [CO(2)](a). These contrasting responses are associated with larger AM hyphal networks, and structural advances in vascular plant water-conducting systems, promoting P transport that enhances AM efficiency at 440 p.p.m. [CO(2)](a). Our results suggest that non-vascular land plants not only faced intense competition for light, as vascular land floras grew taller in the Palaeozoic, but also markedly reduced efficiency and total capture of P as [CO(2)](a) fell.

In vitro antioxidant activities of endophytic fungi isolated from the liverwort Scapania verrucosa.

We investigated in vitro antioxidant activities of 49 endophytic fungi isolated from the liverwort Scapania verrucosa. Based on morphological and molecular identification, the endophytic fungi isolated were classified into seven genera (Hypocrea, Penicillium, Tolypocladium, Chaetomium, Xylaria, Nemania, and Creosphaeria), all belonging to one family (Xylariaceae). By screening with the 2,2'-azino-di(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) decolorization assay, the ethyl acetate extracts of five endophytic fungi (T7, T21, T24, T32, and T38 strains), which exhibited remarkable Trolox equivalent (TE) antioxidant capacity (ranging from 997.06 to 1248.10 µmol TE/g extract), were selected and their antioxidant capacity was further evaluated by assays for 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, hydroxyl radical scavenging, reducing power, and ferrous ion chelating. The ethyl acetate extracts of two endophytic fungi (T24 and T38) were found to have comparable scavenging abilities on both DPPH-free radicals (93.9 and 88.7%, respectively, at 50 µg/mL) and hydroxyl radicals (97.1 and 89.4%, respectively, at 2 mg/mL) when compared with those of the positive controls (ascorbic acid and butylated hydroxytoluene, respectively). Although their reducing powers were similar to that of butylated hydroxytoluene, as indicated by absorbance (0.35 and 0.30 at 50 µg/mL, respectively), only the T38 strain's ethyl acetate extract showed ferrous ion chelating ability (92.9% at 1 mg/mL) comparable to that of the EDTA-2Na control. These endophytic fungi in S. verrucosa are a potential novel source of natural antioxidants.

Aneuraceae (Metzgeriales) and tulasnelloid fungi (Basidiomycota): a model for early steps in fungal symbiosis.

A total of 35 population samples of the liverwort genera Aneura (A. pinguis) and Riccardia (R. latifrons, R. multifida, and R. palmata) were sampled from diverse habitats and geographical provenances in Germany, Austria, and Switzerland. Light and transmission electron microscopy were used to characterise the morphological features of the associations, and phylogenetic analyses based on internal transcribed spacers (ITS) and the D1/D2 regions of the fungal 28S rDNA were used to address diversity and phylogenetic relationships. By comparing the cellular structures of the plant-fungus interactions, we recognised the following states of fungal colonisation within the thalli: fungus-free, epiphytic, intercellular, and intracellular. Colonising hyphae showed dolipores with imperforate parenthesomes, slime bodies, and multilayered walls. Colonised liverwort cells had pleomorphic nuclei and elongated starch-free chloroplasts with distinctive grana. Our analyses revealed six phylogenetic groups of tulasnelloid fungi associated with liverworts, where major lineages mostly share similar host and/or ecological specialisations. The mode of colonisation of the tulasnelloid mycobionts in Aneura and Riccardia sharing identical fungal sequences is different. Consequently, the mode of colonisation may be host-dependent. Finally, our findings demonstrate that Aneuraceae are model organisms for evolutionary studies of symbiotic associations between liverworts and fungi.

Methylobacterium marchantiae sp. nov., a pink-pigmented, facultatively methylotrophic bacterium isolated from the thallus of a liverwort.

A pink-pigmented, facultatively methylotrophic bacterium, designated strain JT1(T), was isolated from a thallus of the liverwort Marchantia polymorpha L. and was analysed by using a polyphasic approach. Comparative 16S rRNA gene sequence analysis placed the strain in a clade with Methylobacterium adhaesivum AR27(T), Methylobacterium fujisawaense DSM 5686(T), Methylobacterium radiotolerans JCM 2831(T) and Methylobacterium jeotgali S2R03-9(T), with which it showed sequence similarities of 97.8, 97.7, 97.2 and 97.4 %, respectively. However, levels of DNA-DNA relatedness between strain JT1(T) and these and the type strains of other closely related species were lower than 70 %. Cells of JT1(T) stained Gram-negative and were motile, rod-shaped and characterized by numerous fimbriae-like appendages on the outer surface of their wall (density up to 200 µm(-2)). Major fatty acids were C(18 : 1)ω7c and C(16 : 0). Based on the morphological, physiological and biochemical data presented, strain JT1(T) is considered to represent a novel species of the genus Methylobacterium, for which the name Methylobacterium marchantiae sp. nov. is proposed. The type strain is JT1(T) ( = DSM 21328(T)  = CCUG 56108(T)).

Structural changes to a mycothallus along a latitudinal transect through the maritime and sub-Antarctic.

Previous studies have shown the leafy liverwort Cephaloziella varians to associate consistently with fungi, typically the ericoid mycorrhizal symbiont Rhizoscyphus ericae, across a wide latitudinal gradient in the maritime and sub-Antarctic. Hitherto, however, there are no quantitative data on the intensity of colonisation of C. varians by fungal structures in the natural environment and how colonisation might vary with changing environmental conditions. A study is hence reported showing that the frequency of colonisation by fungal structures of C. varians alters along a latitudinal transect from South Georgia (54° S, 38° W) to Moutonnée Valley on Alexander Island (71° S, 68° W). The percentage of stem length colonised by dark septate (DS) hyphae increased significantly along the transect, from 30% at South Georgia to 97% at Moutonnée Valley. In contrast, the percentage of stem length colonised by hyaline hyphae decreased significantly, from 85% at South Georgia to 13% at Moutonnée Valley, and that colonised by hyphal coils similarly decreased from 71% at the former location to 15% at the latter. The frequencies of DS hyphae were negatively associated with mean annual and seasonal air temperatures, whereas those of hyaline septate hyphae and hyphal coils were positively associated with air temperatures. Coils at northerly locations were more convoluted than those at southerly locations. The data indicate that hyphal coils, usually associated with nutrient exchange between partners in ericoid mycorrhizas, do form in C. varians tissues in the maritime and sub-Antarctic, but that the frequency of these structures diminishes in colder habitats.